Locate the trim screws on the dishwasher door. Remove the screws and loosen or remove the trim. Remove the old door panel.
Measure the old door panel, including the depth. Transfer the measurements to the transparent polycarbonate panel with a permanent marker.
Cut along the lines with a utility knife. Make several strokes, cutting halfway through the polycarbonate panel.
Align the scored line of the polycarbonate panel along the edge of a countertop or workbench. Hold the panel in place while pressing down firmly on the excess material. The panel will break along the scored edge.
Wipe the polycarbonate panel with a rag dipped in rubbing alcohol to remove dust and oils.
Place the polycarbonate panel face down onto newspapers or a drop cloth. Apply several light coats of a polycarbonate model spray paint over the panel until it's completely covered. Allow it to dry between coats according to the manufacturer's directions.
Insert the new polycarbonate panel onto the door, with the paint on the inner side of the panel. By placing the panel with the transparent polycarbonate on the outside, the paint is protected from damage as you load and unload the dishwasher. Replace the trim and screws.